Cryptocurrency has no environmental impact
Bitcoin's proof-of-work mining is extremely energy-intensive. A 2023 UN University study found that during 2020 to 2021, Bitcoin mining consumed 173 TWh of electricity, comparable to the energy use of a country the size of Pakistan, and produced carbon emissions equivalent to burning 84 billion pounds of coal.
What we know
Bitcoin's proof-of-work consensus mechanism requires miners worldwide to compete in solving computationally intensive cryptographic puzzles. The energy cost of this competition is a deliberate security feature, as it makes the blockchain expensive to attack. However, it also results in very large electricity consumption.
The Cambridge Centre for Alternative Finance (CCAF), which tracks Bitcoin energy use in near real-time, estimated in 2025 that Bitcoin consumed approximately 138 TWh annually, representing about 0.5 percent of global electricity consumption. A UN University study covering 2020 to 2021, published in Earth's Future, found consumption of 173 TWh, resulting in carbon emissions equivalent to burning 84 billion pounds of coal. The study also identified significant water and land footprints associated with cooling infrastructure and the electricity grid areas used.
The energy mix used for Bitcoin mining is evolving but remains substantially fossil fuel-dependent. A 2025 CCAF survey reported that approximately 43 percent of mining electricity came from renewables, while natural gas (38 percent), nuclear (10 percent), and coal (9 percent) made up the rest. Separate US-focused research found that US mining operations sourced 85 percent of their electricity from fossil fuels in 2022 to 2023.
Proof-of-stake cryptocurrencies like Ethereum (which switched consensus mechanisms in 2022) use dramatically less energy than proof-of-work systems. The blanket claim that 'cryptocurrency' has no environmental impact is false for Bitcoin and other proof-of-work coins. The claim is more defensible for proof-of-stake systems but requires careful qualification.
Common claims
- Bitcoin mining uses no significant energy.False. Bitcoin uses approximately 138-173 TWh per year, comparable to a mid-sized country.
- All cryptocurrency is environmentally neutral.False for proof-of-work coins; largely true for proof-of-stake coins like Ethereum.
- Bitcoin mining is powered mostly by renewable energy.Partly false. As of 2025, roughly 43% is renewable; 57% is non-renewable or unverified.